Current state of work in the field of standard handbook data on the structure of inorganic molecules in the gas phase

1992 ◽  
Vol 33 (2) ◽  
pp. 191-196
Author(s):  
S. M. Tolmachev
Keyword(s):  
Gas Phase ◽  
Handbook Data ◽  
Current State ◽  
Standard Handbook ◽  
Inorganic Molecules

Analysis of the Gas Phase Epitaxy of Silicon Carbide as a Basic Process for Power Elec-tronics Technology. Review

2020 ◽  
Vol 25 (6) ◽  
pp. 483-396
Author(s):  
A.V. Afanasev ◽  
◽  
V.A. Ilyin ◽  
V.V. Luchinin ◽  
S.A. Reshanov ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Gas Phase ◽  
Epitaxial Layers ◽  
Power Devices ◽  
High Quality ◽  
Main Method ◽  
Technological Factors ◽  
Current State ◽  
Individual Task ◽  
Technology Review

Currently, chemical gas deposition is the main method for producing high-quality and reproducible epitaxial layers for commercial silicon carbide (SiC) power devices. Based on the experience of ETU «LETI» in the synthesis of monocrystalline SiC, an analysis of the current state of silicon carbide gas phase epitaxy (CVD) technology was carried out. It has been shown that modern CVD reactors allow to implement the growth processes of SiC epitaxial structures of high quality with the following parameters: substrates diameter up to 200 mm; thicknesses of epitaxial layers from 0.1 to 250 μm; layers of n - and p -types conductivity with ranges of doping levels 10-10 cm and 10-10 cm, respectively. At the same time, setting up the technology of the reproducible high-quality growth of epitaxial layers is an individual task for a specific type of reactor. It requires a detailed consideration of the technological factors presented in this paper, which at the end determine the achievable parameters of SiC-epitaxial products

Theoretical Study of Molecular Contamination on Silicon Wafers: Kinetics

1998 ◽  
Vol 41 (5) ◽  
pp. 36-43 ◽  
Author(s):  
Sheng-Bai Zhu
Keyword(s):  
Gas Phase ◽  
Theoretical Study ◽  
Material Selection ◽  
Silicon Wafers ◽  
Surface Kinetics ◽  
Simple Formulation ◽  
Gas Phase Molecules ◽  
Inorganic Molecules ◽  
Molecular Contaminants ◽  
Mass Transport Mechanisms

In an earlier paper ["Theoretical Study of Molecular Contaminants on Silicon wafers: Interactions Between Molecular Contaminants and the Silicon Surface," Journal of the IEST, July/August 1998] a simple formulation was developed to describe interactions between gas phase molecules and solid surfaces.1 Adsorption energies of various organic/inorganic molecules on silicon wafer surfaces were derived, In this paper, the relationship between the gas phase molecule concentration and the surface contamination density based on simple kinetic theories is established. The most important approximations in this derivation include the neglect of possible chemical reactions on the surface and the assumption that gas phase concentrations of pollutants are constants, both in time and in location. The mass transport mechanisms are ignored. With these approximations, the equilibrium in surface kinetics can be reached almost instantly for all the molecules investigated, even for those having activation energies as high as ∼ 72 kJ/mole. This agrees with the experimental data for moisture adsorption on stainless steel.2 A guide is provided for material selection.

Experimental Gas-phase Halogen Nuclear Quadrupole Coupling Constants; A Review

1998 ◽  
Vol 53 (6-7) ◽  
pp. 615-619
Author(s):  
Michael H. Palmer
Keyword(s):  
Gas Phase ◽  
Organic Molecules ◽  
Coupling Constants ◽  
Axially Symmetric ◽  
Field Gradients ◽  
Current State ◽  
Tetrahedral Environment ◽  
Quadrupole Coupling ◽  
Phase Data ◽  
Nuclear Quadrupole

Abstract As a preclude to a theoretical study of nuclear quadrupole coupling constants (NQCC), via the electric field gradients at equilibrium, we review the current state of knowledge of gas-phase data for a diverse set of axially symmetric inorganic and organic molecules with symmetries C3v , C∞v , D∞h in particular, where the heavy elements are CI, Br and I with C, Si and Ge hydrides. In most of the cases, the latter elements are in an approximately tetrahedral environment.

scholarly journals Current State of Porous Carbon for Wastewater Treatment

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1651
Author(s):  
Mongi ben ben Mosbah ◽  
Lassaad Mechi ◽  
Ramzi Khiari ◽  
Younes Moussaoui
Keyword(s):  
Wastewater Treatment ◽  
Porous Materials ◽  
Porous Carbon ◽  
Review Paper ◽  
Research Field ◽  
Separation And Purification ◽  
Porous Carbons ◽  
Current State ◽  
Inorganic Molecules ◽  
Physical And Chemical

Porous materials constitute an attractive research field due to their high specific surfaces; high chemical stabilities; abundant pores; special electrical, optical, thermal, and mechanical properties; and their often higher reactivities. These materials are currently generating a great deal of enthusiasm, and they have been used in large and diverse applications, such as those relating to sensors and biosensors, catalysis and biocatalysis, separation and purification techniques, acoustic and electrical insulation, transport gas or charged species, drug delivery, and electrochemistry. Porous carbons are an important class of porous materials that have grown rapidly in recent years. They have the advantages of a tunable pore structure, good physical and chemical stability, a variable specific surface, and the possibility of easy functionalization. This gives them new properties and allows them to improve their performance for a given application. This review paper intends to understand how porous carbons involve the removal of pollutants from water, e.g., heavy metal ions, dyes, and organic or inorganic molecules. First, a general overview description of the different precursors and the manufacturing methods of porous carbons is illustrated. The second part is devoted to reporting some applications such using porous carbon materials as an adsorbent. It appears that the use of porous materials at different scales for these applications is very promising for wastewater treatment industries.

Gas Phase and Gas Surface Kinetics of Transient Silicoin Hydride Species

1993 ◽  
Vol 334 ◽  
Author(s):  
Joseph M. Jasinski
Keyword(s):  
Thin Films ◽  
Gas Phase ◽  
Silicon Hydride ◽  
Surface Kinetics ◽  
Current State ◽  
The Absolute ◽  
Kinetics Of

AbstractThis paper presents a summary of the current state of our understanding of the absolute reactivity of transient silicon hydride species, such as SiH, SiH2and SiH3in the gas phase and at the surface of thin films.

—Review Paper—Current State-Of-The-Art Measurements Of Ozone In The Gas Phase And In Solution

1988 ◽  
Vol 10 (4) ◽  
pp. 353-365 ◽  
Author(s):  
Gilbert Gordon ◽  
Gilbert E. Pacey ◽  
William J. Cooper ◽  
Rip G. Rice
Keyword(s):  
Gas Phase ◽  
Review Paper ◽  
State Of The Art ◽  
Current State

scholarly journals Gas-Phase Synthesis of Functional Nanomaterials

Applied Nano ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 25-58
Author(s):  
Vladimir N. Popok ◽  
Ondřej Kylián
Keyword(s):  
Gas Phase ◽  
Composite Films ◽  
Chemical Properties ◽  
Industrial Applications ◽  
Cluster Beam ◽  
Soft Landing ◽  
Current State ◽  
History Of ◽  
Pros And Cons ◽  
Physical And Chemical

Nanoparticles (NPs) of different types, especially those of metals and metal oxides, are widely used in research and industry for a variety of applications utilising their unique physical and chemical properties. In this article, the focus is put on the fabrication of nanomaterials by means of gas-phase aggregation, also known as the cluster beam technique. A short overview of the history of cluster sources development emphasising the main milestones is presented followed by the description of different regimes of cluster-surface interaction, namely, soft-landing, pinning, sputtering and implantation. The key phenomena and effects for every regime are discussed. The review is continued by the sections describing applications of nanomaterials produced by gas aggregation. These parts critically analyse the pros and cons of the cluster beam approach for catalysis, formation of ferromagnetic and superparamagnetic NPs, applications in sensor and detection technologies as well as the synthesis of coatings and composite films containing NPs in research and industrial applications covering a number of different areas, such as electronics, tribology, biology and medicine. At the end, the current state of the knowledge on the synthesis of nanomaterials using gas aggregation is summarised and the strategies towards industrial applications are outlined.

scholarly journals The Good, the Bad, and the Ugly: “HiPen”, a New Dataset for Validating (S)QM/MM Free Energy Simulations

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 681 ◽  
Author(s):  
Fiona Kearns ◽  
Luke Warrensford ◽  
Stefan Boresch ◽  
H. Woodcock
Keyword(s):  
Free Energy ◽  
Gas Phase ◽  
Convergence Criteria ◽  
Free Energies ◽  
Acceptance Ratio ◽  
Current State ◽  
Energy Perturbation ◽  
Energy Simulations ◽  
Molecular Description ◽  
Bennett’S Acceptance Ratio

Indirect (S)QM/MM free energy simulations (FES) are vital to efficiently incorporating sufficient sampling and accurate (QM) energetic evaluations when estimating free energies of practical/experimental interest. Connecting between levels of theory, i.e., calculating Δ A l o w → h i g h , remains to be the most challenging step within an indirect FES protocol. To improve calculations of Δ A l o w → h i g h , we must: (1) compare the performance of all FES methods currently available; and (2) compile and maintain datasets of Δ A l o w → h i g h calculated for a wide-variety of molecules so that future practitioners may replicate or improve upon the current state-of-the-art. Towards these two aims, we introduce a new dataset, “HiPen”, which tabulates Δ A g a s M M → 3 o b (the free energy associated with switching from an M M to an S C C − D F T B molecular description using the 3ob parameter set in gas phase), calculated for 22 drug-like small molecules. We compare the calculation of this value using free energy perturbation, Bennett’s acceptance ratio, Jarzynski’s equation, and Crooks’ equation. We also predict the reliability of each calculated Δ A g a s M M → 3 o b by evaluating several convergence criteria including sample size hysteresis, overlap statistics, and bias metric ( Π ). Within the total dataset, three distinct categories of molecules emerge: the “good” molecules, for which we can obtain converged Δ A g a s M M → 3 o b using Jarzynski’s equation; “bad” molecules which require Crooks’ equation to obtain a converged Δ A g a s M M → 3 o b ; and “ugly” molecules for which we cannot obtain reliably converged Δ A g a s M M → 3 o b with either Jarzynski’s or Crooks’ equations. We discuss, in depth, results from several example molecules in each of these categories and describe how dihedral discrepancies between levels of theory cause convergence failures even for these gas phase free energy simulations.

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